Figure 3. Detection of apoptosis in human oral SCC cell lines. (A) TUNEL staining in human oral SCC cell lines. A TUNEL assay was performed 24 hrs after 20 µM of 15-d-PGJ₂ or troglitazone treatment. The results shown are from a representative experiment from a total of 3 that were performed. Scale bar = 10 µm. (B) Effect of 15-d-PGJ₂ or troglitazone on intracellular nucleosome enrichment. The nucleosome concentration after 20 µM of 15-d-PGJ₂ or troglitazone treatment was examined with a cell-death detection kit for the indicated periods of time. Control cells were assigned a value of 1, and other values were expressed relative to these and were plotted against the time after treatment. Data are expressed as mean ± SD (n = 3). *p < 0.05, **p < 0.01.